The instant invention relates to the adjustment of the parameters for optimal piecing operations of a piecing device when changing batches on a rotor spinning machine. When batches are changed it is necessary to reset the machine data of the rotor spinning machine for a piecing joint on an empty bobbin and for a piecing joint after yarn breakage.
Forming a piecing joint on an empty bobbin when piecing is necessary when starting the rotor spinning machine or after a replacement of a bobbin on a spinning box. The formation of a piecing joint is however also necessary after breakage at a spinning station in order to continue yarn production on a yarn bobbin.
The SYNCRO TOP piecing technique to be used for this on the rotor spinning machine is described in detail in point 3.7 of the report of
Kriechbaum, K., Messmer, S.
Importance of piecing joint quality in rotor spinning for further processing--Presentation of a new piecing process
Pages 1-23
Report on the occasion of the 9th spinning mill colloquium on May 4/4 in Enningen.
When batches are changed on the rotor spinning machine it becomes necessary, due to a different type of material and/or yarn number to change the delivery speed and the feeding speed among other things and to replace the rotors used until then with rotors with different diameters. This means different machine data. At the same time the technological parameter of the piecing joint and the parameters for bobbin change had to be entered manually into the piecing device in case of batch change. Both are called piecing joint parameters below. This was expensive and awkward. As a function of these piecing joint parameters and machine data, the piecing joint was produced. The piecing joint parameters influence the aspect of the piecing joint as shown in the above cited article, page 14, FIG. 15. At the same time a distinction had to be made between piecing joints on an empty bobbin and piecing joints after yarn breakage, so that a number of different piecing joint parameters had to be entered by the operator in the state of the art.
The need to enter a number of machine data and piecing joint parameters when changing batches required specialized technological training and a high degree of concentration on the part of the operator in order avoid operator errors. In actual operation however, many operator errors occurred due to multiple input of data or due to the utilization of less qualified operating personnel. It was also a disadvantage for the operating personnel that, together with the parameter input, its effect on the piecing process had to be known. Also, the relatively high number of parameters to be entered at the piecing device in case of batch change proved to be a disadvantage.